A cop walks into a donut shop may sound like the start of a joke, but
fighting counterfeit donuts is no laughing matter for Dunkin' Donut. When
they suspect that a franchise store is selling fake donuts, they send
in specially trained undercover agents:

"I used to be able to reach in and pull out a donut, and be
able to smell and determine whether it was a Dunkin' Donut," Michael
Mershimer, former head of loss prevention for Dunkin' Donuts and Quiznos,
told ABCNews.com.

Dunkin' Donuts didn't just rely on Mershimer's nose. It has a lab
in Canton, Mass., where Dunkin' investigates fraudulent pastries with
the zeal of a forensics team. Donuts are weighed, measured, taken apart
by experts in white lab coats. They are tasted, sniffed and mashed to
see how they crumble.

Across America's thousands of franchise restaurants are more than
300,000 undercover food cops, pulling apart donuts, inspecting sub sandwiches,
and checking burger patties for authenticity. The mystery shoppers are
part of a loss prevention strategy that tries to ensure major brands
- Quiznos, Baskin Robbins, Burger King - maintain consistency and don't
lose money to crafty franchise owners.